Surface-finishing device



March 26, 1929. A HAWN l SURFACE FINISHING' DEVICE Filed April 28, 1927l v l I1/Wenko@ $55297' fyf/ff/y r l f fltfozueq Patented Mar. 26, 1929.

UNITED STATES 1,706,402 PATENT OFFICE.

ALBERT I.` HAWN, OIF DENVER, COLORADO, ASSIGNOR 0F ONE-HALF T0 DOROTHY iSTEPHENSON HAWN, 0l," DENVER, COLORADQ.

sUnFAcE-FINIsHING DEVICE Application iiled April 28,

This invention relates to a device and a medium for rubbing downsurfaces. It is more particularly designed for rubbing down the variouscoats of lacquer, enamel or varnlsh upon the body of an automobile, butwillvbe found valuable in any application requiring a similar action.

The principal object of the invention is to provide a motor operatedrubbing surface to which a liquid or a mixtureeof a liquid and anabrasive will be Constantly fed.

Another object of the invention is to so construct t-he device that. theliquid will be fed at the vortex of a rotating surface so that i it willbe spread evenly outwjardly by the rotating action.

A further object is to provide a medium for use with the device whichwill embody an abrasive in a binder so that, as the binder wears down,new abrasive surfaces will be constantly exposed.

Other objects and advantages reside in the detail construction oftheinvention, which is designed for simplicity, economy and eliiciency.These will become more apparent from lthe following description.

In the following detailed description of the invention, l reference ishad to the accompanying drawing which forms a part hereof. `Likenumerals refer to like parts in all views of the drawing and throughoutthe de- Scription. l

In the drawing: c f Fig. 1 is a side elevation, partly in section,

of my improved surface finishing device.

Fig. 2 is a rear elevation thereof.

Fig. 3 is a detail view illustrating my im proved rubbing down medium.

The invention comprises an electric motor 10, the shaft 1l of whichextends entirely through both motor faces. An axial passage 1 14 extends`the entire length of the shaft 11 opening to vboth extremities thereof.The motor 10 is provided with a handle 12 from which a triggeroperatedswitch 13 is easily accessible for controlling the motor.

On one extremity of the shaft 11 a rubbing disc 15 is carried. The disc15 is formed of comparatively soft rubber or similar resilient materialand is vulcanlzed around a sp1der 16 carried on a collar 33 which issecured to the shaft 11 by means of a suitable set screw 17. In the disc15 a central passage` 18jis formed which communicates with the passage14. The face of the disc 15 is concave as 1927. Serial No. 187,228.

the disc has been Worn down to these layers,

they will indicate to the operator that the disc should be discarded orreplaced before the spider 16 is exposed to cause damage'to v thesurface being worked on.

On the rear of the motor 10 a packing gland plate 21 is secured aboutthe shaft 11 to which is clamped a cap 22 by meanslof suitable screws23. As the cap is screwed in place, it will compress packing 24 aroundthe shaft within the gland plate 21 and a packing washer 25 against thegland plate 21 to insure a liquid tight seal about the shaft 11 andbetween the cap 22 and the gland plate 21.

Fromthe cap 22 a feed passage 26 leads to a needle valve 27 whichcontrols the entrance of iuid 'to the cap from a nipple 28. The

fluid is led to the nipple 28 through a iexible hose 29 which passesthrough the handle 12 and slips over the extremity of the nipple 28. Thehose 29 is attached to an electric feed cable 30 which supplies currentto the motor 10'by means of suitable clips 31. In this way the electriccable and Huid hose act as a single unit and are easily handled by theoperator.

The rubbing disc 15 may be of plain rubber in which case an abrasivesubstance such as emery, carborundum, pumice stone, or the like, isadmixed with a suitable fluid, depending upon the surface beingfinished, such as rubbing oil or water. This mixture is fed to the disc15 through the passage 18. The disc,

however, may be formed as illustrated in Fig. 3, of a rubber or similarresilient base material in which the articles of abrasives, indicated at32, areem edded or vulcanized. By this construction asy the disc wearsaway new abrasive particles are being constantly presented to the rubbedsurface, rubbing 011 or water being fed through the passage.

In use, the operator sets the needle valve 27 to deliver the propersupply of liquid to the disc 15. Then itis only necessary to place thedisc against the surface and work it thereover. The iexible edges of thedisc will bend backwardl flattening out the concavity 19 entirely. heentire disc surface then contacts with the rubbed surface with equalpressure. The natural centrifugal action of the rotating disc will Workthe liquid uni? formly toward its periphery.

While a specic form of the improvement has been described andillustrated herein, it is desired to be understood that the same may bevaried, Within the scope of the Vappended claims, Without departing fromthe spirit of the invention.

Having thus described the invention, what Iclaiin and desire to secureby Letters Patent 1s 1. A surface olishing disc comprising a circulardisc of exible material; a spider em- 15 bedded in ysaid material; and acollar carried by said spider and adapted to connect with an operatingshaft; and a layer of fabric embedded in said material over said spider.

2. A surface polishing disc comprising a circular disc of flexiblematerial; a spider embedded in said material; a collar carried by saidspider and adapted to connect with an operating shaft; and a layer offabric embedded in said material over said spider7 said ydisc having acentral passage communicating therethrough and adapted to connect with asimilar passage in said shaft.

In testimony whereof, 'I affix my signature.

ALBERT I. HAWN. y

